DVD backups work using slide card but CDR backups wont load

I'm having no problems playing DVD backups using the slide card, but when I try a CD backup the game halts abut hlafway during loading(happen to Live 2004 and Backyard Wrestling). im using a Pioneer 106 drive and Nero Ultra edition 6. i've tried both Memorex and Generic CDRs with the same result. someone suggested CDRW and that wouldnt load at all. When burning DVD I burn at 4x(once again with no problems), when doing CDS I burn at 16x. Any suggestions? i know the first reply will be 'Burn at 1x', but are their any other ideas in case that doesn't work.